Prefer require_relative for internal requires

`require_relative` is preferred over `require` for files within the same
project because it uses paths relative to the current file, making code
more portable and less dependent on the load path.

This change updates internal requires to use `require_relative` for
consistency, performance, and improved portability.

Ref:
- ruby/psych#522
- ruby/logger#20
- ruby/rdoc#658
- rubocop/rubocop#8748

Author: tagliala

lib/haml.rb

@@ -1,13 +1,14 @@
 # frozen_string_literal: true
-require 'haml/engine'
-require 'haml/error'
-require 'haml/version'
-require 'haml/template'
+require_relative 'haml/engine'
+require_relative 'haml/error'
+require_relative 'haml/version'
+require_relative 'haml/template'
 
 if File.basename($0) != 'haml'
   begin
     require 'rails'
-    require 'haml/railtie'
+
+    require_relative 'haml/railtie'
   rescue LoadError
   end
 end

lib/haml/attribute_builder.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
-require 'haml/object_ref'
+require_relative 'object_ref'
 
 module Haml::AttributeBuilder
   class << self

lib/haml/attribute_compiler.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
-require 'haml/attribute_builder'
-require 'haml/attribute_parser'
-require 'haml/ruby_expression'
+require_relative 'attribute_builder'
+require_relative 'attribute_parser'
+require_relative 'ruby_expression'
 
 module Haml
   # The list of boolean attributes. You may add custom attributes to this constant.

lib/haml/attribute_parser.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
-require 'haml/ruby_expression'
+require_relative 'ruby_expression'
 
 module Haml
   class AttributeParser

lib/haml/cli.rb

@@ -1,5 +1,6 @@
 # frozen_string_literal: true
-require 'haml'
+require_relative '../haml'
+
 require 'thor'
 
 module Haml
@@ -76,7 +77,9 @@ def generate_code(file)
       if options[:actionview]
         require 'action_view'
         require 'action_view/base'
-        require 'haml/rails_template'
+
+        require_relative 'rails_template'
+
         handler = Haml::RailsTemplate.new
         template = ActionView::Template.new(template, 'inline template', handler, { locals: [] })
         code = handler.call(template)

lib/haml/compiler.rb

@@ -1,12 +1,12 @@
 # frozen_string_literal: true
-require 'haml/compiler/children_compiler'
-require 'haml/compiler/comment_compiler'
-require 'haml/compiler/doctype_compiler'
-require 'haml/compiler/script_compiler'
-require 'haml/compiler/silent_script_compiler'
-require 'haml/compiler/tag_compiler'
-require 'haml/filters'
-require 'haml/identity'
+require_relative 'compiler/children_compiler'
+require_relative 'compiler/comment_compiler'
+require_relative 'compiler/doctype_compiler'
+require_relative 'compiler/script_compiler'
+require_relative 'compiler/silent_script_compiler'
+require_relative 'compiler/tag_compiler'
+require_relative 'filters'
+require_relative 'identity'
 
 module Haml
   class Compiler

lib/haml/compiler/children_compiler.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
-require 'haml/temple_line_counter'
+require_relative '../temple_line_counter'
 
 module Haml
   class Compiler

lib/haml/compiler/script_compiler.rb

@@ -1,7 +1,8 @@
 # frozen_string_literal: true
 require 'temple/static_analyzer'
-require 'haml/ruby_expression'
-require 'haml/string_splitter'
+
+require_relative '../ruby_expression'
+require_relative '../string_splitter'
 
 module Haml
   class Compiler

lib/haml/compiler/tag_compiler.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
-require 'haml/util'
-require 'haml/attribute_compiler'
-require 'haml/string_splitter'
+require_relative '../util'
+require_relative '../attribute_compiler'
+require_relative '../string_splitter'
 
 module Haml
   class Compiler

lib/haml/engine.rb

@@ -1,15 +1,16 @@
 # frozen_string_literal: true
 require 'temple'
-require 'haml/parser'
-require 'haml/compiler'
-require 'haml/html'
-require 'haml/string_splitter'
-require 'haml/escape'
-require 'haml/escape_any'
-require 'haml/force_escape'
-require 'haml/dynamic_merger'
-require 'haml/ambles'
-require 'haml/whitespace'
+
+require_relative 'parser'
+require_relative 'compiler'
+require_relative 'html'
+require_relative 'string_splitter'
+require_relative 'escape'
+require_relative 'escape_any'
+require_relative 'force_escape'
+require_relative 'dynamic_merger'
+require_relative 'ambles'
+require_relative 'whitespace'
 
 module Haml
   class Engine < Temple::Engine

lib/haml/escape.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
-require 'haml/util'
+require_relative 'util'
 
 module Haml
   class Escape < Temple::Filters::Escapable

lib/haml/escape_any.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
-require 'haml/escape'
+require_relative 'escape'
 
 module Haml
   # This module allows Temple::Filter to dispatch :fescape on `#compile`.

lib/haml/filters.rb

@@ -1,20 +1,20 @@
 # frozen_string_literal: true
-require 'haml/filters/base'
-require 'haml/filters/text_base'
-require 'haml/filters/tilt_base'
-require 'haml/filters/coffee'
-require 'haml/filters/css'
-require 'haml/filters/erb'
-require 'haml/filters/escaped'
-require 'haml/filters/javascript'
-require 'haml/filters/less'
-require 'haml/filters/markdown'
-require 'haml/filters/plain'
-require 'haml/filters/preserve'
-require 'haml/filters/ruby'
-require 'haml/filters/sass'
-require 'haml/filters/scss'
-require 'haml/filters/cdata'
+require_relative 'filters/base'
+require_relative 'filters/text_base'
+require_relative 'filters/tilt_base'
+require_relative 'filters/coffee'
+require_relative 'filters/css'
+require_relative 'filters/erb'
+require_relative 'filters/escaped'
+require_relative 'filters/javascript'
+require_relative 'filters/less'
+require_relative 'filters/markdown'
+require_relative 'filters/plain'
+require_relative 'filters/preserve'
+require_relative 'filters/ruby'
+require_relative 'filters/sass'
+require_relative 'filters/scss'
+require_relative 'filters/cdata'
 
 module Haml
   class Filters

lib/haml/filters/base.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
-require 'haml/util'
+require_relative '../util'
 
 module Haml
   class Filters

lib/haml/filters/plain.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
-require 'haml/string_splitter'
+require_relative '../string_splitter'
 
 module Haml
   class Filters

lib/haml/force_escape.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
-require 'haml/escape'
+require_relative 'escape'
 
 module Haml
   # This module allows Temple::Filter to dispatch :fescape on `#compile`.

lib/haml/parser.rb

@@ -2,8 +2,9 @@
 
 require 'ripper'
 require 'strscan'
-require 'haml/error'
-require 'haml/util'
+
+require_relative 'error'
+require_relative 'util'
 
 module Haml
   class Parser

lib/haml/rails_helpers.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: false
-require 'haml/helpers'
+require_relative 'helpers'
 
 # There are only helpers that depend on ActionView internals.
 module Haml

lib/haml/rails_template.rb

@@ -1,8 +1,9 @@
 # frozen_string_literal: true
 require 'temple'
-require 'haml/engine'
-require 'haml/rails_helpers'
-require 'haml/util'
+
+require_relative 'engine'
+require_relative 'rails_helpers'
+require_relative 'util'
 
 module Haml
   class RailsTemplate

lib/haml/railtie.rb

@@ -4,7 +4,7 @@
 module Haml
   class Railtie < ::Rails::Railtie
     initializer :haml, before: :load_config_initializers do |app|
-      require 'haml/rails_template'
+      require_relative 'rails_template'
     end
   end
 end

lib/haml/template.rb

@@ -1,7 +1,8 @@
 # frozen_string_literal: false
 require 'temple'
-require 'haml/engine'
-require 'haml/helpers'
+
+require_relative 'engine'
+require_relative 'helpers'
 
 module Haml
   Template = Temple::Templates::Tilt.create(